Refrigerant to water heat exchanger

ABSTRACT

A heat exchanger having at least one inner conduit comprising of a second tubular member coaxially disposed within a first tubular member, wherein the second tubular member outer surface is in contact with the first tubular member inner surface. Each of the first and second tubular members is composed of a material with an approximately 0.015 inch maximum wall thickness.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.14/216,471, filed Mar. 17, 2014, which claims the benefit of U.S.Provisional Patent Application Ser. No. 61/817,347 filed Apr. 30, 2013and all the benefits accruing therefrom under 35 U.S.C. § 119, thecontents of which in their entirety are herein incorporated byreference.

TECHNICAL FIELD OF THE DISCLOSED EMBODIMENTS

The presently disclosed embodiments generally relate to heat transferdevices, and more particularly, to a refrigerant-to-water heatexchanger.

BACKGROUND OF THE DISCLOSED EMBODIMENTS

A heat exchanger is a device used to passively transfer heat from onematerial to another. These materials may be liquid or gaseous, dependingon the situation in which the heat exchanger is being utilized. Heatexchangers are basically two chambers separated by a heat transmittingbarrier

Typical refrigerant-to-water heat exchangers, are available as coaxialheat exchangers or brazed plate heat exchangers. Coaxial heat exchangersconsist of a double-walled corrugated copper tube inserted through alarger steel tube. Heat exchange takes place as water flows through thecenter of the corrugated copper tube and a refrigerant flows between thecorrugated copper and steel tubes. A double-walled coaxial heatexchanger, using corrugated copper, typically requires a 0.060-0.080inch wall thickness of the corrugated copper tube. There is therefore aneed for a double-walled heat exchanger with thinner walls.

SUMMARY OF THE DISCLOSED EMBODIMENTS

In one aspect, a refrigerant-to-water heat exchanger is provided. Theheat exchanger includes an outer conduit, and at least one inner conduitdisposed within the outer conduit.

In one embodiment, an inner conduit includes a first tubular member, anda second tubular member coaxially disposed within the first tubularmember. In one example, the first tubular member is formed from a copperrefrigeration tube having a 5/16 inch outer diameter with anapproximately 0.015 inch maximum wall thickness. In another example, thefirst tubular member has a wall thickness of approximately 0.010-0.015inch. In another example, the first tubular member has a wall thicknessless than approximately 0.010 inch. In one example, the second tubularmember is formed from a copper refrigeration tube having anapproximately 0.015 inch maximum wall thickness. In another example, thesecond tubular member has a wall thickness of approximately 0.010-0.015inch. In another example, the second tubular member has a wall thicknessless than approximately 0.010 inch. In another embodiment, the firsttubular member and the second tubular member may be formed from aluminumrefrigeration tubing. In one example, the inner surfaces of the firsttubular member and the second tubular member include enhancementsdisposed therein. The enhancements include depressions formed byextruding continuous pieces of material longitudinally throughout theinner surfaces of the first tubular member and the second tubular memberto increase the surface area thereof.

In one example, the second tubular member is expanded within the firsttubular member such that the protrusions of the inner surface of thefirst tubular member are in contact with the outer surface of the secondtubular member.

In one embodiment, a first liquid, for example a refrigerant, flowsthrough the inner conduit, and a second liquid, for example water, flowsbetween the outer conduit and the inner conduit. As hot refrigerantflows through the inner conduit and water flows between the outerconduit and the inner conduit, heat transfers from the inner conduitinto the water to be distributed.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments and other features, advantages and disclosures containedherein, and the manner of attaining them, will become apparent and thepresent disclosure will be better understood by reference to thefollowing description of various exemplary embodiments of the presentdisclosure taken in conjunction with the accompanying drawings, wherein:

FIG. 1. shows a perspective view of a refrigerant-to-water heatexchanger in an exemplary embodiment;

FIG. 2 shows a cross-sectional view of a refrigerant-to-water heatexchanger in an exemplary embodiment; and

FIG. 3 shows a cross-sectional view of an inner conduit utilized in arefrigerant-to-water heat exchanger in an exemplary embodiment; and

FIG. 4 shows a schematic flow chart of an exemplary method ofconstructing a refrigerant-to-water heat exchanger.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It will nevertheless be understood that no limitationof the scope of this disclosure is thereby intended.

FIG. 1 illustrates an exemplary embodiment of a refrigerant to waterheat exchanger, indicated generally at 10. Particularly, as shown inFIG. 2, the heat exchanger 10 includes an outer conduit 12 and at leastone inner conduit 14 disposed within the outer conduit 12. In anotherembodiment, the outer conduit 12 may be removed.

FIG. 3 illustrates an exemplary embodiment of an inner conduit 14. Innerconduit 14 includes a first tubular member 16 with an approximately0.015 inch maximum wall thickness. In another embodiment, the firsttubular member 16 has a wall thickness of approximately 0.010-0.015inch. In another embodiment, the first tubular member 16 has a wallthickness of less than approximately 0.010 inch. The first tubularmember 16 includes a first tubular member outer surface 18 and a firsttubular member inner surface 20. In one embodiment, the first tubularmember inner surface 20 includes enhancements 22 disposed therein. Theenhancements 22 include depressions within the first tubular innersurface 20 formed by extruding continuous pieces of materiallongitudinally throughout the first tubular inner surface 20 to create avent path between the first tubular inner surface 20 and a secondtubular outer surface 26.

The inner conduit 14 further includes a second tubular member 24coaxially disposed within the first tubular member 16. In an exemplaryembodiment, the second tubular member 24 has an approximately 0.015 inchmaximum wall thickness. In one embodiment, the second tubular member 24has a wall thickness of approximately 0.010-0.015 inch. In anotherembodiment, the second tubular member 24 has a wall thickness of lessthan approximately inch. The second tubular member 24 includes thesecond tubular member outer surface 26 and a second tubular member innersurface 28. In one embodiment, the second tubular member inner surface28 includes enhancements 30 disposed therein. The enhancements 30include depressions within the second tubular inner surface 28 formed byextruding continuous pieces of material longitudinally throughout thesecond tubular inner surface 28 to increase the surface area thereof. Inan exemplary embodiment of an inner conduit 14, the second tubularmember outer surface 26 is in contact with the enhancements 30 formed inthe first tubular member inner surface 20. In another embodiment, thesecond tubular member outer surface 26 includes enhancements 30 disposedtherein. The enhancements 30 include depressions within the secondtubular outer surface 26 formed by extruding continuous pieces ofmaterial longitudinally throughout the second tubular outer surface 26.In one embodiment of an inner conduit 14, the enhancement 30 formed inthe second tubular member outer surface 26 is in contact with the firsttubular member inner surface 20.

In an exemplary embodiment, the first tubular member 16 is composed ofcopper. In another embodiment, the first tubular member 16 is composedof aluminum. In an exemplary embodiment the second tubular member 24 iscomposed of copper. In another embodiment, the second tubular member 24is composed of aluminum. The first tubular member 16 and the secondtubular member 24 may be composed of any material that exhibits thedesired heat transfer properties for a given application. The outerconduit 12 may be composed of any desired material such as steel orplastic to name a few non-limiting examples.

In an exemplary embodiment, the inner conduit 14 is configured to allowa first liquid to flow therethrough. In one embodiment, the first liquidis a refrigerant. In an exemplary embodiment, the outer conduit 12 isconfigured to allow a second liquid to flow therethrough. In oneembodiment, the second liquid is water.

In an exemplary embodiment, the inner conduit 14 may be formed by using5/16 inch refrigeration tubing as the first tubular member 16 and using7 millimeter refrigeration tubing as the second tubular member 24.Because the 7 millimeter refrigeration tubing has an outer diameter thatis less than the inner diameter of the 5/16 inch refrigeration tubing,the 7 millimeter refrigeration tubing may be inserted into the 5/16 inchrefrigeration tubing in a coaxial arrangement. Thereafter, an object,for example a steel ball attached to a rod, further attached to adriving mechanism may be inserted into the interior of the 7 millimeterrefrigeration tubing and run along the entire length of the 7 millimeterrefrigeration tubing, thereby expanding the diameter of the 7 millimeterrefrigeration tubing and bringing the outer surface of the 7 millimeterrefrigeration tubing into contact with the enhancements 22 on the innersurface of 5/16 inch refrigeration tubing to form the inner conduit 14.In some embodiments, application of the object also expands the diameterof the 5/16 inch refrigeration tubing, forming an inner conduit 14 witha diameter larger than 5/16 inch. Therefore, as shown in FIG. 4, anexemplary method 100 of constructing a heat exchanger 10 includes thestep 102 of inserting a first refrigeration tube, including a firstinner surface, a first outer surface, and having a first diameter, intoa second refrigeration tube, including a second inner surface, a secondouter surface, and having a second diameter. Step 104 includes expandingthe first refrigeration tube within the second refrigeration tube,wherein the first outer surface is in contact with the second innersurface, thereby forming an inner conduit. In one embodiment, the methodfurther includes the step 106 of inserting at least one inner conduitinto an outer conduit.

It will be appreciated that, because the inner conduit 14 consists of afirst tubular member 16 and second tubular member 24, each having a0.015 inches maximum wall thickness, less material than a double-walledcorrugated copper heat exchanger can be used for construction thereofand provide sufficient heat transfer between a refrigerant and water.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly certain embodiments have been shown and described and that allchanges and modifications that come within the spirit of the inventionare desired to be protected.

What is claimed is:
 1. A method for constructing a heat exchanger from afirst refrigeration tube, and a second refrigeration tube, the methodcomprising: (a) inserting the first refrigeration tube, including afirst inner surface, a first outer surface, and having a first diameterinto a second refrigeration tube, including a second inner surfaceincluding continuous enhancements formed longitudinally therein, asecond outer surface, and having a second diameter; and (b) expandingthe first refrigeration tube within the second refrigeration tube tobring the first outer surface into contact with the enhancements of thesecond inner surface, thereby forming an inner conduit.
 2. The method ofclaim 1 further comprising inserting the inner conduit into an outerconduit.
 3. The method of claim 1, wherein step (b) comprises placing anobject in the interior of the first refrigeration tube, and mechanicallydriving the object through the entire length of the first refrigerationtube.
 4. The method of claim 2, wherein the object comprises a steelball attached to a rod.
 5. A method for constructing a heat exchangerfrom a first refrigeration tube, and a second refrigeration tube, themethod comprising: (a) inserting the first refrigeration tube, includinga first inner surface, a first outer surface, including continuousenhancements formed longitudinally therein, and having a first diameterinto a second refrigeration tube, including a second inner surface, asecond outer surface, and having a second diameter; and (b) expandingthe first refrigeration tube within the second refrigeration tube tobring the enhancements of the second outer surface into contact with thefirst inner surface, thereby forming an inner conduit.
 6. The method ofclaim 5 further comprising inserting the inner conduit into an outerconduit.
 7. The method of claim 5, wherein step (b) comprises placing anobject in the interior of the first refrigeration tube, and mechanicallydriving the object through the entire length of the first refrigerationtube.
 8. The method of claim 7, wherein the object comprises a steelball attached to a rod.